前驱体制备方法对电池正极材料电性能的影响

Effects of Precursor Preparation on Electrical Properties of Cathode Materials for Lithium Ion Batteries

采用氢氧化物共沉淀法和碳酸盐共沉淀法制备4种三元LiNi_(1/3)Mn_(1/3)Co_(1/3)O_2前驱体,然后再采用高温煅烧工艺制得LiNi_(1/3)Mn_(1/3)Co_(1/3)O_2。碳酸盐共沉淀法采用碳酸氢钠作为沉淀剂,氢氧化物共沉淀法分别采用氢氧化钠(正向和逆向加入)、氢氧化钠和氨水作为沉淀剂。通过X射线衍射、扫描电子显微镜、电化学性能测试等方法系统地研究了前驱体制备方法对三元锂离子电池正极材料电性能的影响。结果表明:碳酸盐共沉淀法制得的LiNi_(1/3)Mn_(1/3)Co_(1/3)O_2体颗粒呈现类球形,与有氨水参与的氢氧化物共沉淀法沉淀产物的形貌基本相似。在1 C、3~4.3 V下充放电,不同前驱体制备的LiNi_(1/3)Mn_(1/3)Co_(1/3)O_2首次放电比容量依次为147.0,145.8,140.2,138.1 m A·h/g,循环50周后依次为135.2,131.1,119.3,113.6 m A·h/g,容量保持率为92.0%、89.9%、85.2%、82.1%。

Four kinds of （Ni1/3 C01/3 Mn1/3 ） （OH）2 powders were synthesized from co - precipitated and co precipitation method. Then, LiNi1/3Mn1/3Co1/3O2 was prepared by high temperature calcination. The precipitating agent is sodium bicarbonate, including sodium hydroxide （forward and reverse） , sodium hydroxide and ammonia. The effects of precursor preparation methods on the electrical properties of cathode materials for lithium ion batteries were systematically investigated by means of X - ray diffraction to scan electron microscopy and electrochemical performance measurements. The results show that the LiNi1/3 Mn1/3 Co1/3O2 particles obtained by carbonate co precipitation method were spherical. The morphology of the precipitated product was similar to that of the co precipitation method. In voltage range of 3 - 4.3 V, the first discharge specific capacity of LiNi1/3Mn1/3 Co1/3O2 prepared by different precursors was 147, 145.8, 140.2, 138.1 mA·h/g. The capacity retention rate was 92% 89.9% , 85.2% and 82.1%.